The effectiveness of physical activity interventions in Asian children and adolescents: a systematic review.

OBJECTIVE: The objective of this review is to investigate the effectiveness of interventions to promote physical activity (PA) among children and adolescents in Asian countries. STUDY DESIGN: Systematic review. METHODS: A systematic search of eight electronic databases was performed to retrieve articles published between January 1990 and August 2019, in English language, including any interventions to promote PA outcomes among children (aged 3-12 years) and adolescents (aged 13-18 years) in Asian countries. RESULTS: Thirty studies met the eligibility criteria and were included. Most studies were school-based (70%, n = 21), and half were cluster randomized controlled trials (53%, n = 16). Twelve of 30 included studies were among children, 15 among adolescents, and three among both children and adolescents. Only four studies (13%) used device-based measures of PA. The duration of intervention ranged from one day to 60 months (median 4.5 months). Twenty-one studies were of moderate-to-high quality, of which 15 demonstrated significant increases in PA behavior or physical fitness. Evidence was found that school-based, short-term (up to six months) interventions with a single or multicomponent approach including PA sessions, physical education, health education, and/or educational materials may increase overall PA in Asian children and adolescents. CONCLUSIONS: The present review provides some evidence supporting the effectiveness of interventions in promoting PA-related outcomes. However, the findings are inconsistent due to the low number of studies, low-methodological quality, and/or small sample size. Well-designed interventions are needed to inform strategies to enhance PA engagements among children and adolescents in Asia.

Sugar-sweetened beverage intake and relative weight gain among South African adults living in resource-poor communities: longitudinal data from the STOP-SA study.

OBJECTIVES: This study examines the prospective association between sugar-sweetened beverages (SSB) consumption and change in body weight over a 4-5-year period in a socio-economically disadvantaged South African population. METHODS: This is a longitudinal study involving 800 adults (212 men, 588 women); 247 from the original METS (Modelling the Epidemiological Transition Study) cohort (N = 504) and 553 of the original 949 members of the PURE (Prospective Urban and Rural Epidemiology) Study. Both cohorts were drawn from low-income, socio-economically disadvantaged communities. Mean follow-up duration and age were 4.5 (SD 0.45) and 50.0 (SD 11.8) years, respectively. Harmonised measurements included body mass index, self-reported moderate-to-vigorous physical activity, and intake of meat, snacks and 'take-aways', fruits and vegetables and SSB (in servings/week). Multivariate logistic regression models were developed to determine the extent to which SSB consumption predicted relative weight gain, after controlling for potential confounders and known predictors. RESULTS: Nearly a third (29%) of participants had a relative weight change ≥5.0%; higher in the non-obese compared to the obese group (32% vs. 25%; p = 0.026). The average SSB consumption was 9.9 servings/week and was higher in the food insecure compared to the food secure group (11.5 vs. 9.0 servings/week; p = 0.006); but there were no differences between women and men (10.3 vs. 9.1 servings/week; p = 0.054). Mean SSB consumption was higher in the group who gained ≥5% weight compared to those who did not (11.0 vs. 8.7; p = 0.004). After adjustment, SSB consumption of 10 or more servings/week was associated with a 50% greater odds of gaining at least 5% body weight (AOR: 1.50, 95% CI (1.05-2.18)). CONCLUSION: These results show that higher intake of SSB predicts weight gain in a sample of South Africans drawn from low-income settings. Comprehensive, population-wide interventions are needed to reduce SSB consumption in these settings.

The relationship between functional status, physical fitness and cognitive performance in physically active older adults: A pilot study.

OBJECTIVE: Ageing is associated with a progressive decline in physical function and cognitive performance which could result in a shift from an independent to a more dependent lifestyle. The aim of this research study was to assess the fitness, functional performance and cognitive ability in independently living older South Africans and to determine which fitness parameters and functional performance tests best explain the variance in cognitive function. DESIGN: Descriptive observational study. PARTICIPANTS: Older adults with a mean age 71±4.7 years (n = 70; 28 men and 42 women) were recruited. Sixty percent of the sample completed at least secondary schooling and more than two-thirds were taking medication for a chronic medical condition. MEASUREMENTS: Self-reported physical activity was assessed using the Yale Physical Activity Survey. Fitness tests included the 6-minute walk test and Bicep Curls. The functional performance tests were; Static and Dynamic balance, Timed Up and Go, Sit to Stand, Grip strength and Functional Reach. The Stroop Task and 6-Item cognitive impairment test were used to measure cognitive performance. Bivariate and multivariate analyses were conducted between performance on the novel cognitive Stroop Task and functional and cognitive tests. RESULTS: We found significant relationships between the number of correct responses on the Stroop Task and scores on the 6-Item Cognitive Impairment test (-0.520, p < 0.01) and grip strength (r = 0.42, p< 0.01). The number of incorrect responses was inversely associated with functional reach (r = -0.445, p< 0.01). The final regression model included: age, dynamic balance, right arm grip strength and the score on the 6-item cognitive impairment test, and explained 44% of the variance in performance of the Stroop Task. CONCLUSIONS: The results of this study showed that measures of physical function were associated with cognitive performance even in highly functioning older South African adults. Further research is needed to determine the extent to which exercise training can improve functional capacity and the effect on cognitive performance.

Cardiovascular fitness is associated with bias between self-reported and objectively measured physical activity.

The aim of this research study was to determine whether the level of agreement between self-reported and objective measures of physical activity (PA) is influenced by cardiovascular fitness. Participants (n = 113) completed the Global Physical Activity Questionnaire (GPAQ), a health risk assessment and a sub-maximal 12-minute step test. Age-predicted VO2max was used to classify participants as lower fit and higher fit (HF). ActiGraph (GT3X) accelerometers were worn for 7 consecutive days. Matthews cut points were used to calculate minutes of moderate and vigorous PA (MVPA) per week. Bland-Altman plots were used to measure limits of agreement between GPAQ and ActiGraph MVPA. The participants' mean age was 37.9 ± 12.7 years and more than 60% were categorised as HF (n = 71). Moderate PA was over-reported in 39% of all participants. Most of the over-reporters for moderate PA were in the HF group (64.1%). Vigorous PA was over-reported by 72.6% of all participants. The discrepancy between self-reported and objective measures of vigorous PA increased with increasing self-reported time spent in vigorous PA. Fitter individuals appear to over-report PA more than lesser fit participants, suggesting that fitness could influence the level of agreement between self-reported and objective measures of PA.

Innovative strategies targeting obesity and non-communicable diseases in South Africa: what can we learn from the private healthcare sector?

Over 50% of South African adult women and 30% of adult men are either overweight or obese, and nearly half of all adults are insufficiently active, with major increases in obesity-associated healthcare expenditures since 1980, a high proportion of which are paid by private health insurance. In this paper, we describe the Vitality programme, an incentivized health promotion programme from South Africa's largest private health insurer, Discovery Health, with over 2.5 million beneficiaries. Wellness activities of the programme include health risk assessments, subsidized gym memberships and smoking cessation or weight loss programmes with many incentives, including cash back on purchases of healthy foods. This incentive-based programme has shown a significant relationship between levels of engagement in wellness activities, in particular increasing participation in fitness-related activities, with lower healthcare expenditure and an increase in the overall ratio of healthy foods to total food purchases. This programme demonstrates that incentives may reduce the barriers for entry into care, increase preventive screening and increase engagement in healthy behaviours for prevention and management of obesity. This 'carrots versus sticks' approach may have implications for public health policy even in lower- and middle-income settings and underserved communities.

Effectiveness of a community based low intensity exercise program for older adults.

OBJECTIVE: The aim of this study was to assess the effectiveness of a community-based, low-intensity exercise programme in older adults from socio-economically and historically disadvantaged communities. DESIGN: Three community centres were selected: two were allocated to the same 20-week, twice-weekly exercise program (EX1, n=38; EX2, n=32); and a third to relaxation classes (control/CTL; n=21). Measurements at baseline, 10 and 20 weeks included field tests for anthropometry, static and dynamic balance, gait, upper and lower body strength, 6-minute walk test, blood pressure, activities of daily living (ADL), instrumental activities of daily living (IADL), physical activity recall and self perceived health status. RESULTS: Exercise training significantly improved dynamic balance in both groups (75.1+/-31.5 vs 55.3+/-13.6 s, and 53.3+/-17.0 vs 37.0+/-10.4 s, for EX1 and EX2, respectively, p < 0.001 compared to CTL (57+/-27 vs 53+/-15 s). Lower body strength, as measured by the number of sit-to-stand repetitions in 10 s was also significantly improved in both EX1 and EX2 (p<0.001). No significant changes occurred in the CTL group. Systolic blood pressure decreased in both EX1 and EX2 from baseline to 20 weeks (147.8+/-12.8 vs 143.9+/-3.3 mmHg and 143.0+/-13.9 vs 137.4+/-14.5 mmHg, respectively, p<0.009, compared to CTL (147+/-13 to 150+/-16 mmHg). Furthermore, in a sub sample of subjects who were hypertensive at the outset, exercise intervention was associated with a significant decrease in systolic blood pressure (n=26; 146+/-14 mmHg to 140+/-14 mmHg; p=0.005). Variables unaffected by exercise training were upper body strength, body composition and fat distribution, 20 m walk, cardiovascular endurance, time spent in recreational activities, self perceived health status and ADL. CONCLUSION: A community-based, low intensity exercise programme improved dynamic balance and lower body strength in community dwelling older adults and improved blood pressure, particularly in those who were hypertensive.

Development of a novel nutrition screening tool for use in elderly South Africans.

OBJECTIVE: To develop a nutrition screening tool for use in older South Africans. DESIGN: A cross-sectional validation study in 283 free-living and institutionalised black South Africans (60+ years). METHODS: Trained field-workers administered a 24-hour recall and the Mini Nutritional Assessment (MNA) screening tool, and performed anthropometric measurements and physical function tests. Cognitive function was assessed using a validated version of the Six-Item Cognitive Impairment Test. Biochemical indicators assessed included serum albumin, haemoglobin, ferritin, vitamin B12, red-blood-cell folate, cholesterol and vitamin C. The MNA was used as the gold standard against which a novel screening tool was developed using a six-step systematic approach, namely: correspondence analysis; identification of key questions; determination of internal consistency; correlational analyses with objective measures; determination of reference cut-off values for categories of nutritional risk; and determination of sensitivity and specificity. RESULTS: The new screening tool includes nine separate concepts, comprising a total of 14 questions, as well as measurement of mid-upper arm circumference. The new tool score was positively associated with level of independence in either basic activities of daily living (r = 0.472) or the more complex instrumental activities of daily living (r = 0.233). A three-category scoring system of nutritional risk was developed and shown to significantly characterise subjects according to physical function tests, level of independence and cognitive function. The new tool has good sensitivity (87.5%) and specificity (95.0%) compared with the MNA scoring system. It has a very high negative predictive value (99.5%), which means that the tool is unlikely to falsely classify subjects as well nourished/at risk when they are in fact malnourished. CONCLUSION: A novel screening tool has been shown to have content-, construct- and criterion-related validity, and the individual items have been shown to have good internal consistency. Further validation of the tool in a new population of elderly Africans is warranted.

Micronutrient dilution associated with added sugar intake in elderly black South African women.

OBJECTIVES: To investigate the association between added sugar and macronutrient and micronutrient intakes, and to assess whether added sugar intake is related to biochemical indices of nutritional status, Mini-Nutritional Assessment (MNA) score, body mass index (BMI) and performance on physical function tests. DESIGN: A cross-sectional, analytical study. SETTING AND SUBJECTS: Convenient sample of 285 institutionalised and community-dwelling black South African men and women aged 60+ y. METHODS: An interviewer-administered 24-h dietary recall and MNA were performed. Serum albumin, vitamin B12, ferritin, cholesterol, haemoglobin, red blood cell (RBC) folate and plasma vitamin C were measured. Handgrip strength, BMI, 'sit-to-stand' and 'get-up-and-go' tests were measured. Outcome variables were analysed according to tertiles of added sugar, in grams and as a percentage of total energy (% E). RESULTS: In each tertile of sugar intake, mean MNA score fell in the 'at-risk' classification. In women, energy, protein, % E protein, fibre, thiamin, riboflavin, niacin, vitamin B6, folate, pantothenic acid, biotin, vitamin C, calcium, iron, magnesium, phosphorus, zinc, copper and selenium intake were significantly lowest in subjects in the highest % E sugar tertile. In men, no differences were found for micronutrient intake according to tertiles of total added sugar or % E added sugar. Physical function declined with increasing sugar intake, and suboptimal RBC folate and plasma ascorbic acid status was associated with increasing sugar intake (in women). No relationship was found between added sugar intake and the very high prevalence (65%) of obesity in women. CONCLUSION: A nutrient-diluting effect of added sugars intake was demonstrated in elderly black South African women. Further studies in this population are required in order to develop food-based dietary guidelines, which include messages on added sugar intake.

Lifetime physical activity and determinants of estimated bone mineral density using calcaneal ultrasound in older South African adults.

UNLABELLED: Increased levels of physical activity (PA) have been linked to higher peak bone mass and increased bone area. The aim of the study was to identify the association between lifetime and current PA with estimated Bone Mineral Density (BMD) in a population of older, socio-economically disadvantaged South Africans of mixed racial ancestry. METHODS: Estimated BMD and T-scores were measured using calcaneal ultrasound (SAHARATM) in 47 men and 105 women, mean age, 65 +/-7 years. Lifetime PA was assessed using a questionnaire comprised of three activity domains (household, occupational, leisure) during five age epochs (14- 21; 22-34; 35-49; 50-64; > 65 years). Current PA was assessed using the Yale Physical Activity Survey. Peak bone strain units for each activity were estimated, based on impact loading. Confounding factors such as BMI, smoking patterns and nutritional status were also quantified. RESULTS: Men and women had similar mean estimated calcaneal BMD, 0.454+/-0.01 and 0.453+/-0.1g/m2, respectively. The proportion of subjects presenting with apparent osteopenia and osteoporosis was similar in men and women (52% vs. 53% and 7% vs. 6%, respectively). Occupational PA between 14 and 21 years, for men (r=0.35; p=0.034) and 22-34 years for women (r=0.24; p=0.033) was significantly correlated to estimated BMD. There were no other significant associations between any of the PA domains and estimated BMD. Leisure time PA only accounted for 0.8% of total energy expenditure for both the men and women. Individuals who were occupationally active between ages 14 and 34 years, were more likely to remain active throughout life. Smokers had lower estimated BMD and T-scores than non-smokers (p<0.01). Reported alcohol and calcium intake was not correlated to any of the ultrasound parameters. CONCLUSION: Estimated BMD was weakly, but significantly correlated to occupational PA during the years of peak-bone mass accretion, which may be protective against accelerated bone loss in later life. From a public health perspective, these data highlight the importance of quantifying lifetime PA in all domains, including occupation.